Construction of expansion joints



Dec. 9; 1941. E. MEYER HAL 2,265,301

CONSTRUCTION OF EXPANSION JOINTS Filed Aug. 10, 1959 llum fiaUEfie JzZFirin 50 +37 JEN/252 11 511.

Patented Dec. 9, 1941 1 CONSTRUCTION OF EXPANSION JOINTS Ernest Meyer and Gavotte' J. Irwin,-Akron, Ohio, assignors to The B. F. Goodrich Company, New York, N. Y., a corporation of New York Application August 10, 1939, Serial No. 289,406

6 Claims.

This invention relates to the construction of expansion joints in slab floor or pavement constructions, and is particularly useful in connection with the laying of floors and pavements of concrete or other plastic composition.

In the construction of concrete. floors and pavements it is necessary to form the floor or pavement of separate slabs with spaces provided therebetween to compensate for expansion and contraction of the floor or pavement due to changes of temperature. The spaces may be filled with a water-sealing plastic material such as bituminous compositions, or compressible sealing strips of rubber-like material may be emloyed to close the spaces so that water and dirt is prevented from enterin and accumulating in the expansion spaces. For this purpose a resilient rubber expansion joint stripsuch as that of the Dewhirst and Meyer Patent No. 2,156,681 dated May 2, 1939 may be used.

As it is necessary to keep the surface of floors and pavements smooth and free from projections or shoulders, it is usually desired toemploy dowel pins embedded in the adjacent slabs and extending therebetween across the joint-to transfer the paving loads from slab to slab and prevent relative vertical movement of the slabs due to shift ing of road ballast or action of frost'or surface water. v

The problem of providing a removable form to mold the expansion joint space is made more difiicult by the presence of the dowel rods and makes advisable the use of a form which will support the rods in proper position until the slabs are completed and will permit removal of the form from both.

The principal objects of this invention are to provide for conveniently molding the walls of the space while supporting the dowel rods in proper position, to provide ease of placement and vremovability, to provide for forming a rebate to seat a resilient sealing strip between slabs, and to provide conveniently for simultaneous embedding of a lower sealing strip 'in the joint.

These and other objects will appear from the following description and the accompanying drawing. 1

Of the drawing Fig. 1 is a perspective view of the form ready for pouring of the concrete, parts being broken away and parts shown in section.

Fig. 2 is a cross sectional view of a pavement .showing portions ofadjacent concrete slabs, the

dowel pin, and the form and lower sealing strip in place.

Fig. 3 is a perspectiveview of the resilient dowel support.

Fig. 4 is a perspective view of a modified form of the invention, parts being broken away and parts shown in section to illustrate its construction.

Fig. 5 is a perspective view of the bottom sealing strip.

Referring to the drawing, thenumerals III, II designate adjacent spaced slabs of concrete having an expansion space I2 therebetween. To provide for supporting a resilient expansion joint filler at the surface of the slabs, theshoulders of the slabs adjacent the space may be rebated as at I3, I4. A channel shaped resilient strip I5 is provided to seal the space at the bottom so that water cannot enter the joint from below and has wings I6, I! embedded in the concrete. The strip I5 preferably is formed with its inner walls I5a, .I 5b upwardly converging as shown in Fig. 5

so ,tha t it may be mounted upon the form temporarily'.,simply by grippingthe same between suchlwalls without the provision of special attaching devices, and may be'readily detached from the form to leave the strip in the bottom of the expansion void.

Load-transferring dowel rods I8 are embedded in the slabs across the joint. These rods may be of solid metal with clearance spaces provided at their ends in any desired manner as by .use of tubing forms placed over the ends of the rods, or the rods may be of composite telescoping type. In either case the rods may be lubricated before being embedded in the concrete so as to facilitate sliding movement of the rod with respect to the slabs.-

To provide for forming the space I2 a pair of similar strips or plates I9, 20 of strip material such as sheet metal are mounted together in spaced relation by spacing strips 2I, 22 to which the strips I9, 20 are secured by screws 23 or other suitable fastening means.

For clearing the dowel rods so that the form may be removed after adjacent slabs have been formed, V-sha'ped notches or slots 25 are formed in the lower margins ofstrips I9, 20 at the proper intervals. The notches have arcuatev throats having the same radius as the rods I8.

Strips 21, 28 of sheet material having the desired thickness may be aflixed to the exposed faces of strips I9, 20 at their upper margins for forming the rebates I3, I4. If desired, the strip 22 may be omitted as in Fig. 4 and where the strips I9, 20 are of springy metal removal of the form from the poured joint is facilitated by the 2 gringottheplateaandtheablenceofthestrip 'Ihechannelstrip llofresilientmaterialmay conveniently be placed by straddling it about the bottom oi' the form so that its-flanges II, I! extend outwardly above the bottom of the form. The resilience of the strip causes the walls iia. ill: thereof to grip the form, holding the strip temporarily in place. when the concrete is poured 'thereabout the flanges are embedded therein and the channel strip-remains in the concrete when the form is withdrawn.

' The rods It may conveniently be employed for assisting in supporting the form in place. For

this purpose a supporting structure of wire a may. be provided to support the ends of the dowel rods and to support the formmidway of their length. A convenient supporting structure may be provided by welding U-shaped wire members II to straight lengths 32, 33 of similar'wire. the wires 32, 33 being arranged at such a height on the limbs of the U-shaped members 3| as to pro- I .vide supports for the rods while at the same time properly spacing the U-shaped members. Smaller U-shaped wire members 34 may be welded to the members ii at their centers to support the channel strip ll of the form.

. To provide for closing the slots 25 to prevent entrance of concrete at the slots and at the same.

erally of a truncated isosceles triangle as viewed from the side, and adapted resiliently to fill the slots 25. The tops. of the blocks are concavely formed as at 36 to provide a rest for the dowel bars. To provide for holding the blocks in place while permitting the faces of the blocks to lie flush with the outer faces of the form, lugs 31, 38 of less width than the blocks by the combined thickness of the strips It, 2! are provided centrally of the inclined sides of the blocks. These lugs act also as spacers to space the strips I9, 20 apart. After the concrete is formedthe blocks may be removed one at a time from the joint after the form has been-lifted, the resilient pliable properties -of the blocks permitting them to be distorted to remove them from below the dowel rods. The downward pressure of the dowel bars compress the blocks somewhat so that when forced out from beneath the bars; the blocks spring upward and greatly facilitate the removal.

A modified form of independently removable form .of the invention, the block ill is of truncated isosceles form but higher than the tops of the not readily subject to wear and may be used'over and over again;

These and other modifications may be made without departing from the spirit ofthe invention as it is defined by the following claims.

We claim:

l. A form assembly for making an expansion joint, said assembly comprising a form structure having notches in the lower margin thereof for accommodatingload transfer devices, removable spaced-apart blocks of resilient rubber-like material disposed in said notches between the walls of the form beneath said devices to support the latter and close the notches, said blocks being removable independently of one another from the form, and a joint bottom strip of resilient rubberlike material in channel form receiving the bottom margin of the form and said blocks and comprising walls in converging relation adapted to grip the form and the bottom portions of said blocks resiliently between them.

2. A form for an expansion joint between floor or paving slabs, said form comprising a pair of spaced form strips notched ata margin thereof to clear a dowel rod, and a block of resilient rubber-like material adapted to be removably positioned substantially to fill the space between the strips at the notched portion, said block having integral retaining lugs for locating it with respect to the notched portion and for holding it temporarily in place, and said block having a seat for said dowel-rod.

3. Aform for makingan expansion joint, said form comprising a structure notched at its lower margin to accommodate a load-transfer device, and a block of resilient rubber-like material having a seat for said device and being removably positionable in said structure at'the notch in relation to support said device on said seat upon removal of the notched structure from the joint,- said block being of sufflcient length to close the notch opening in the structure, but of a length not substantially greater than its height so as to permit dislodging the block from beneath the load-transfer device by tilting and compressing the block in the joint.

4. A form for making an expansion joint, said form comprising a pair of spaced-apart ,plates dowel rods andwider than the slots 25 and of I the samethickness 'as the space' between the strips I9, 20. A horizontal aperture ii of the shape and size of a dowel rod is formed therethrough at such a height as to support the dowel in the desired position. The block ii is split vertically from the aperture to its base as at 52 silience of the blocks seals the slots in the form against entrance of concrete and permits removal 1 of the blocks after the dowel rods are in place and embedded in the concrete. The blocks are 76 tiallyclosing the notch openingsin the plates and notched at the lower margin thereof to accommodate a load-transfer device, and a block of resilient rubber-like material having a seat for said device and being positionable removably at the notch between the plates in relation to support said device on said seat in the joint upon removal of the plates from the joint, said block being of a size and shape substantially closing the notch opening in the plates and having retaining portions integral therewith and projecting between said plates only a limited extent beyond the notch in such relation as topermit dislodging the block from beneath the load-transfer device by tilting and compressing the block in the joint after removal of said plates. P

5. A form'for making an expansion joint, said form comprising a pair of spaced-apart plates having notches at spacedeapart positions along the lower margin thereof to accommodate spacedapart load-transfer devices, and blocks of resilient rubber-like material having a seat for said device and being positionable removably at the notches between the plates in relation to support said load-transfer devices on said seats in the joint upon removal of the plates from the joint, said blocks being of a size .and shape substan-- having retaining portions integral therewith and projecting between said plates only a limited extent toward one another in such relation as to permit dislodgin each block individually from beneath itsload-transfer device by tilting and compressing the block in the joint.

6. Means for supporting a load-transfer device and closing the notch opening of.an expansion joint form, said means comprising a block of resilient rubber-like material positionable removably at the notch of the form in relation to support the load-transfer device in the joint upon removal of the notched structure from the joint, said block having a seat for said device and being of a size and shape to close substantially the notch opening in the structure and having ears integral therewith and projecting therefrom in off-set relation to the face of the block for re- I ception within said structure beyond the notch to locate and retain the block temporarily in the form.

ERNEST MEYER. GAVO'I'IE J. IRWIN. 

